My Quantum hot water system is rattling when it is heating

There is an anode in some water heaters That us to help keep the tank from corroding. gOnce it deterioritates enough that it no longerhelps protect the tank the tank itselfcan eventually corrode and have a sudden leak.They should last 15-20 years but water Conditions can cause them to fail sooner.There is a small connection on the bottomwhere a hose can be connected to drain the heater.This should be done annually but most peoplenever do it .The electricity or gas and cold water has to be off when this is done.This is supposed to help prolong the life of the heater.The rattling is possibly caused by rusty parts inside the heater.You can drain it and examine the water but that won't changeanything.it may be time to replace it.

Quantum specifications call for the anode to be removed and inspected every fifth year of operation .If it is corroded it should be replaced.There are exact procedures for doing this.The water and the electricity need to be turnedoff during the process.The parts from the corroded anode can be causing the rattle . They can be removed by draining the gm heater.which also requires turning off the water and electricity.